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The characteristic function of row contractions and liftings of row contractions are complete invariants up to unitary equivalence for row contractions and liftings of row contractions, respectively. We provide alternate proofs for these…

Functional Analysis · Mathematics 2023-02-01 Neeru Bala , Santanu Dey , Reshmi M. N

The comonotonic maxitivity property of functionals frequently appears in the characterization of fuzzy integrals based on the maximum operation. In some special cases, comonotonic maxitivity implies monotonicity of functionals. The question…

General Topology · Mathematics 2025-04-21 Taras Radul

Let $X$ be a Hausdorff compact space and $C(X)$ be the algebra of all continuous complex-valued functions on $X$, endowed with the supremum norm. We say that $C(X)$ is (approximately) $n$-th root closed if any function from $C(X)$ is…

Functional Analysis · Mathematics 2008-02-28 N. Brodskiy , J. Dydak , A. Karasev , K. Kawamura

This paper addresses the study and characterizations of variational convexity of extended-real-valued functions on Banach spaces. This notion has been recently introduced by Rockafellar, and its importance has been already realized and…

Optimization and Control · Mathematics 2023-08-29 Pham Duy Khanh , Vu Vinh Huy Khoa , Boris S. Mordukhovich , Vo Thanh Phat

Given a compact of ${\bf R}^n$, there is always a doubling measure having it as its support. We use this fact to construct an integral operator that extends differentiable functions defined on any compact set of ${\bf R}^n$ to the whole of…

Classical Analysis and ODEs · Mathematics 2007-05-23 Jaume Gudayol

Functional representations of the capacity monad based on the max and min operations were considered in \cite{Ra1} and \cite{Ny1}. Nykyforchyn considered in \cite{Ny2} some alternative monad structure for the possibility capacity functor…

General Topology · Mathematics 2019-03-05 Taras Radul

This article explores anti-coproximinal and strongly anti-coproximinal subspaces in the spaces of vector-valued continuous functions and operator spaces. We provide a complete characterization of strongly anti-coproximinal subspaces in $…

Functional Analysis · Mathematics 2025-08-08 Souvik Ghosh , Kallol Paul , Debmalya Sain , Shamim Sohel

We propose to extend ``invertibility'' to ``regularity'' for categories in general abstract algebraic manner. Higher regularity conditions and ``semicommutative'' diagrams are introduced. Distinction between commutative and…

Mathematical Physics · Physics 2007-05-23 Steven Duplij , Wladyslaw Marcinek

In this paper, we first discussed multiplicative metric mapping by giving some topological properties of the relevant multiplicative metric space. As an interesting result of our discussions, we observed that the set of positive real…

General Mathematics · Mathematics 2014-10-13 Muttalip Ozavsar , Adem Cengiz Cevikel

We consider approximations of a continuous function on a countable normed Fr\'{e}chet space by analytic and $*$-analytic. Also we found a criterium of the existence of an extension of a continuous function from a dense subspace of a…

Functional Analysis · Mathematics 2015-05-01 M. A. Mytrofanov , A. V. Ravsky

In this paper, we unify and improve existing results on characterizing strict and almost stricty convex functions via subdifferential mapping, Moreau envelope, and proximal mappings. In particular, it is shown that if a convex function is…

Classical Analysis and ODEs · Mathematics 2026-05-07 Heinz H. Bauschke , Honglin Luo , Xianfu Wang

Real numbers do not admit an extensional procedure for observing discrete information, such as the first digit of its decimal expansion, because every extensional, computable map from the reals to the integers is constant, as is well known.…

Logic · Mathematics 2023-06-22 Auke B. Booij

We consider discrete metric spaces and we look for non-constant contractions. We introduce the notion of contractive map and we characterize the spaces with non-constant contractive maps. We provide some examples to discussion the possible…

Classical Analysis and ODEs · Mathematics 2010-11-19 Fabio Zucca

In this paper, our main aim is to extend a classical theorem of Phelps on norm-attaining functionals from the space of scalar-valued continuous functions $C(\Omega)$ to its vector-valued counterpart $C(\Omega, X)$. One of our main results…

Functional Analysis · Mathematics 2026-04-13 Saurabh Dwivedi

We first prove that for every metrizable space $X$, for every closed subset $F$ whose complement is zero-dimensional, the space $X$ can be embedded into a product space of the closed subset $F$ and a metrizable zero-dimensional space as a…

General Topology · Mathematics 2026-01-13 Yoshito Ishiki

We classify a one-parameter family, $\mathfrak{confcarr}_z(d+1)$, of conformal extensions of the Carroll algebra in arbitrary dimension with $z$ being the anisotropic scaling exponent. We further obtain their infinite-dimensional…

High Energy Physics - Theory · Physics 2025-03-11 Hamid Afshar , Xavier Bekaert , Mojtaba Najafizadeh

Closure space has proven to be a useful tool to restructure lattices and various order structures.This paper aims to provide a novel approach to characterizing some important kinds of continuous domains by means of closure spaces. By…

Logic in Computer Science · Computer Science 2022-02-04 Longchun Wang , Qingguo Li , Lanlun Guo

In this article, we give a full description of a topological many-one degree structure of real-valued functions, recently introduced by Day-Downey-Westrick. We also point out that their characterization of the Bourgain rank of a Baire-one…

Logic · Mathematics 2019-06-26 Takayuki Kihara

We prove that continuous reducibility is a well-quasi-order on the class of continuous functions between separable metrizable spaces with analytic zero-dimensional domain. To achieve this, we define scattered functions, which generalize…

Logic · Mathematics 2024-10-18 Raphaël Carroy , Yann Pequignot

In this paper we indicate a way to generalize a series of fixed point results in the framework of b-metric spaces and we exemplify it by extending Nadler's contraction principle for set-valued functions (see Multi-valued contraction…

Classical Analysis and ODEs · Mathematics 2015-12-15 Radu Miculescu , Alexandru Mihail